Greece Launches Mandatory B2B E-Invoicing for Large Businesses via myDATA

Greece has joined the growing list of EU countries with a mandatory B2B e-invoicing regime. The Greek tax authority (AADE) began phasing in the mandate on 2 March 2026 — a one-month delay from the originally planned date — for resident large businesses with annual turnover above €1 million.

• 2 March 2026: First wave begins — large businesses (turnover > €1m) for domestic B2B transactions and exports outside the EU. Around 38,000 businesses are in scope for this wave.
• 2 May 2026: End of a two-month soft-launch grace period, by which all first-wave businesses must have migrated.
• 1 October 2026: All remaining Greek businesses come into scope, with a transitional period running through the end of the year.

Invoicing to EU-based customers remains optional for e-invoicing purposes under this phase — the mandate currently covers domestic transactions and non-EU exports.

Businesses can comply via certified e-invoicing service providers, AADE's free Timologio app, or direct integration with the myDATA REST API.

Non-compliance carries real financial risk: for VAT-relevant transactions, the fine can reach 50% of the VAT amount associated with the non-compliant transaction. For non-VAT transactions, fixed fines of €500 or €1,000 apply depending on the taxpayer's accounting system.

Businesses that integrate at least two months ahead of their applicable deadline qualify for tax incentives, including 100% additional depreciation on e-invoicing equipment/software in the year of purchase and a 100% increase in deductible expenses related to invoice production, transmission, and archiving during the first 12 months.

AADE (Greek Independent Authority for Public Revenue) myDATA e-invoicing guidance.